Table 1.

Characteristics of studies included in the systematic review and meta-analysis

First Author	Year	Single vs. Multi Center	Type of Study	Clinical Setting	N	Years of Follow Up		Age Range	Percent Male	Length of Hospital Stay in Daysa	AKI definition severity	Duration of AKI		Study Quality	Different covariates adjusted for
						Mean	Max					Short, medium or long	Transient or Persistent
Brown	2010	Single	R	Cardiac surgery	4987	2.6	5	64–72	29–33	6–24.	AKIN	√		Fair	age, sex, prior CABG, COPD, emergency surgery, ejection fraction and baseline eGFR
Coca [7]	2010	Multi	R	Non cardiac	35,302	3.8	9	66–88	96–98	6	AKIN	√		Good	age, sex, race, chronic insulin use, operative time, ASA class 4/5, emergency surgery, baseline GFR, smoking status,weight loss > 10% last 6 months, chronic alcohol intake, COPD, pre-op albumin, hematocrit,WBC, and hemoglobin A1C
Choi [11]	2010	Multi	R	General Hospital	17,325	5.7	20	44–47	98	NM	AKIN		√	Fair	Age, sex, race, baseline GFR, albuminuria, viral load, cd4, htn, dm, lung ds, smoking, cancer, ICU admission
Goldberg [19]	2009	Single	R	Post MI	1957	1.5	5	59–70	76	NM	AKIN		√	Fair	age, gender, estimated GFR (MDRD), previous diuretic therapy, HTN,DM, smoking, previou MI, heart rate and blood pressure on admission, use of reperfusion therapy ACE/ARB and beta-blockers), and left ventricular EF.,
Han [12]	2013	Single	R	ICU	2143	0.4	0.5	68	52–68	13–29	KDIGO	√		Fair	Age, sex, Apache, primary diagnosis, underlying CKD, history of malignancy, the need for mechanical ventilation, the use of vasoactive drugs, and AKI stages
Loef [26]	2004	Single	R	Cardiac surgery	843		8.3	62–64	73	1–5	AKI/ No AKI			Fair	Age, PVD,Operation time, pre op renal function by cockroft-gault formula,post op renal function deterioration
TRIBE-AKI [21]	2016	Multi	P	Cardiac surgery	1199	3		71–73	66–76	7–32	AKIN	√		Good	Age, sex, race, elective surgery, preop GFR, DM, HTN, CHF, MI,surgery type and center
Wu [14]	2015	Single	R	Intensive	318	8		65.6	71	31	KDIGO	√		Good	age, gender, need for a ventilator, emergent operation and baseline renal function; severity of sepsis, the use of vasoactive drugs and diuretics, surgery category; APACHE II, MODS, SOFA scores and peak KDIGO stage.
Yoo [13]	2014	Single	P	General Hospital	123	0.65	3.4	64.8	61	39	AKIN	√		Good	Age, sex, charlson comorbity index, recovery
Pannu [20]	2013	Multi	R	General Hospital	190,714	2.8	6	63–66	47–53	NM	KDIGO		√	Good	age, sex, MI, PVD,CVA,CHF,DM, nondermatologic malignancy, baseline estimatedGFR,requirement for acute dialysis, primary diagnostic code for hospitalization, CIHI resource intensity weight.
Liano [19]	2006	Single	R	General Hospital	413	7.2	22	57.8	66	54	ATN/ No ATN		√	Poor	Age, sex, type of admission, ATN etiology, need for RRT, ARF functional severity, ICU admission,incidence of comorbity factors
Uchino [27]	2010	Single	R	General Hospital	20,126		2	65–78	49–56	NM	RIFLE		√	Fair	Age, sex, emergency admission, ICU admission,mech ventilation,baseline Cr in mg/dl,operation time
Wamock [28]	2015	Single	R	General Hospital	50,580	28		55	55–63	4–8	AKI/ No AKI		√	Fair	Age, race, sex, charlson comorbid index, admission source, egfr < 60
Gammelager [10]	2014	Multi	R	ICU	21,550	2.7	3	57–68	53–61	8–23	KDIGO		√	Fair	age, gender, other ischemic heart diseases, CVA,HTN, PVD, CKD cancer, surgical status, primary diagnosis during current hospitalization, and preadmission use of drugs
Welton [29]	2007	Single	R	Cardiac surgery	1324	6	10	66	80	NM	AKI/ No AKI		√	Good	Age, sex, HTN, DM, smoking,Hl, COPD, BMI,Prior MI and coronary revascularization,angina, CHF, baseline Cr Clearance, medications, and short term complications.
Heung [9]	2015	Single	R	General Hospital	104,764		13	61.8	95	7	KDIGO	√		Good	Age, race, sex, preadmission,DM, HTN,Dx of sepsis, need for mechanical ventilation during index hospitalization, length of stay,charlson comorbity score and baseline GFR.
Sood [30]	2014	multi	R	ICU	5443	0	0	55–70	57	NM	RIFLE		√	Good	Demographics, illness severity, co-morbidity,and treatment
Perinel [31]	2015	multi	R	ICU	447	0	0	45–75	63.3	NM	AKIN		√	Good	Age, type of AKI, use of vasopressors, illness severity

R Retrospective, P Prospective, AKIN Acute Kidney Injury Network, HIV Human Immunodeficiency Virus, NM Not Mentioned, ICU- Intensive Care Unit, KDIGO Kidney Disease: Improving Global Outcomes, ATN Acute Tubular Necrosis, RIFLE Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease classification, AMI Acute myocardial infarction, DM Diabetes Mellitus, HTN Hypertension, PVD Peripheral vascular Disease, CHF Congestive heart failure, MI Myocardial infarction, BMI Body mass index, CVA Cerebrovascular accident, Dx Diagnosis, Cr Creatinine

^aMedian days of length of hospitalization as reported by authors